Terms of use.

These terms are the deal between you and Luft (lufthq.com and the Luft companion extension for Chrome). Using Luft means you agree to them. The privacy policy covers your data.

The beta

Luft is in an invite-only beta. Features can change, move between plans or go away, and things can break. We'll give notice before big changes where we can, and your data stays exportable.

Your account

• You need to be 13 or older. Under 18 (or the age of adulthood where you live), a parent or guardian needs to agree to these terms for you.
• One account per person. Use an email you control and keep it safe: whoever can read it can sign in as you.
• Link only a chess.com account that's yours. Verifying proves it, and a username verified by its owner is released from any other Luft account.
• Guests on shared boards don't need an account, but these terms apply to them too.

Play fair

Don't:

• Use Luft for help during a game in progress, on chess.com or anywhere else. Analysis is for after the game.
• Harass, threaten or impersonate anyone, or put offensive names or content on shared boards.
• Scrape or bulk download Luft, or use bots or automated tools on it (the site and the companion are the way in).
• Attack, probe or overload the service, or get around Free's limits, rate limits or access controls.
• Use Luft to break the law or chess.com's own rules.

The limiter

The limiter is a self-help tool. It counts the games it can see and blocks new ones once you hit your limit, but it can miss a game, count late, or be turned off by removing the extension. It helps you keep a promise to yourself; it doesn't guarantee you will.

Plans and payments

• Free stays free: the limiter, your streak and every course's main lines, with Free's limits listed on the pricing page.
• Pro isn't on sale yet. During the beta everyone may get Pro features free; when paid plans launch, accounts without free access or a subscription go back to Free.
• When Pro goes on sale, prices are on the pricing page, a plan renews until you cancel, and you can cancel any time. Trials, renewals and refunds will be spelled out here before you can buy anything.
• Free access we give you (a grant or a promo code) lasts as long as we said and can't be swapped for money.

chess.com and Lichess

Luft is independent. It isn't affiliated with, endorsed by or sponsored by Chess.com or Lichess. Chess.com is a trademark of its owner. Luft reads only chess.com's public data, and your use of chess.com stays under chess.com's terms.

Our content and credits

• Luft's site, app, courses, text and design are ours. Use them for your own chess study; don't copy or republish them.
• The opening courses are built from the Lichess open database of games and evaluations, and the puzzles come from the Lichess puzzle database, all released into the public domain under CC0 at database.lichess.org. Opening names come from Lichess's chess-openings list (CC0). Thanks, Lichess.
• Analysis runs Stockfish in your browser (Stockfish.js, GPLv3). Piece art: the cburnett set by Colin M.L. Burnett, BSD license.

Your content

What you put into Luft (feedback, board names, the names you use, your moves) stays yours. You let us store it and show it to the people you share it with, only to run Luft. Ideas and feedback you send, we can use to improve Luft without owing you anything. Don't post anything you don't have the right to.

Ending things

• You can leave any time: export your data and delete your account from your account page.
• We can suspend or close an account that breaks these terms or puts Luft or other people at risk. Where it's reasonable, we'll tell you why and let you export first.
• We may end the beta or shut Luft down. If we do, we'll give notice and time to export your data.

No warranties

Luft is provided as is and as available. As far as the law allows, we don't promise it will always be up, free of bugs, or right about every move. Engine evaluations, accuracy, ratings and suggestions are estimates.

Limits on liability

As far as the law allows, we aren't liable for indirect, incidental, special or consequential losses, or for lost data, profits or rating points. Our total liability for any claim about Luft is limited to the greater of what you paid us in the 12 months before the claim and US$50. Nothing in these terms takes away rights you have under the consumer laws where you live.

Disputes

If something goes wrong, write to us first and we'll try to sort it out together.

Changes

We may update these terms; the date at the top says when. For changes that matter, we'll tell you in the app or by email before they apply. If you don't agree, you can delete your account; using Luft after that means you accept them.

Contact

Questions about these terms: hello@lufthq.com.